Carburetors comprising an automatic auxiliary starting device



Dec. 13, 1966 A. L. MENNESSON CARBURETORS COMPRISING AN AUTOMATICAUXILIARY STARTING DEVICE Original Filed April 5, 1962 2 Sheets-Sheet 1MN mi isv N NN HVVFNTOR flrvm Laws HEM/Essen E? H y. ip/ms f l/QM/Z;

ATTORNEY Dec. 13, 1966 L. MENNESSON CARBURETORS COMPRISING AN AUTOMATICAUXILIARY STARTING DEVICE 2 Sheets-Sheet 2 Original Filed April :5, 1962N VE TOR fill/DRE Lou/5 HAW/Essa 57% 051-140 H1 5% A ##URN E .7

United States Patent 3,291,462 CARBURETORS COMPRISING AN AUTOMATICAUXILIARY STARTING DEVICE Andr Louis Mennesson, Neuilly-sur-Seine,France, as-

signor to Societe Industrielle de Brevets & dEtudes S.I.B.E.,Neuilly-sur-Seine, France, a society of France Continuation ofapplication Ser. No. 184,787, Apr. 3,

1962. This application May 18, 1966, Ser. No. 551,068

Claims priority, application France, Apr. 15, 1961,

2 Claims. (Cl. 26139) This application is a continuation of my pendingapplication Serial No. 184,787, filed April 3, 1962, now abandoned.

The invention relates to internal combustion engine carburetorscomprising an auxiliary device to increase the fuel feed for coldstarting conditions and abutment means for controlling the idlingthrottle opening, said abutment means being capable of increasing thisopening for running with cold engine, said auxiliary device and abutmentmeans being operated automatically in accordance with the temperature ofthe engine.

In my US. patent of November 5, 1963, No. 3,109,874, filed March 24,1961, for Improvements in Carburetors Comprising an Auxiliary Device toIncrease the Fuel Feed for Cold Starting Conditions, I described acarburetor in which the above mentioned abutment means consist of athermostatic device comprising a material, contained in a closedhousing, undergoing an important variation of volume when passing in areversible fashion from one physical state to another one, and inparticular from the solid state to the liquid state, between thetemperatures to which said material is to be subjected according as theengine is cold or warm, respectively, such a device being capable ofdeveloping an effort greater than the force exerted by the resilientreturn means acting upon the throttle valve.

According to the present invention the carburetor is characterized bythe fact that said thermostatic device acts not only upon the throttlevalve but also upon the auxiliary starting device, this starting deviceconsisting preferably of an unbalanced choke valve, i.e. a valve mountedon a shaft off-set from the center of induction pipe so that the airflow through this pipe will tend to open the valve against theresistance of resilient means.

Preferred embodiments of the present invention will be hereinafterdescribed with reference to the appended drawings given merely by way ofexample and in which:

FIG. 1 is a diagrammatic elevational view, with parts in section, of acarburetor made according to the present invention;

FIG. 2 is a half-section view on the line IIII of FIG. 1;

FIG. 3 is a view similar to FIG. 1 showing the carburetor with itselements in the position corresponding to idling when the engine iswarm;

FIG. 4 shows a modification of a detail of FIG. 1.

The general construction of the carburetor with the exception of themeans for controlling the throttle valve idling position and the openingof the choke valve may be of any type. In the example shown by thedrawings, the carburetor comprises an induction pipe 1 having at the topthereof an air inlet 2 in which is provided a choke valve 3 mounted on ashaft 4, this shaft being off-set with respect to the center of theinduction pipe so that the air flow through said induction pipe willtend to open said valve. Downstream of said choke valve 3 are located,successively, in pipe 1, a venturi 5 and a cylindrical portion in whichis mounted a throttle valve 6 carried by a spindle 7. Throttle valve 6is opened by the driver through a throttle control 8 which acts, in thedirection of the arrow of FIG. 1, upon a lever 9 fixed on spindle 7, thethrottle valve being constantly urged toward its closed position by aspring 10. The primary mixture of air and fuel (not shown) opens intoventuri 5.

The abutment means serving to determine the position of throttle valve 6in idling position consist essentially of an oscillating lever 21rotatable freely about spindle 7 and the lower part 21a of whichcooperate with an element rigid with throttle valve 6. In theconstruction shown by the drawing, this element consists of a screw 22mounted in a lug 23 rigid with spindle 7. Lug 23 may further carry, asshown, a second screw 34 which coopcrates with an abutment 35 rigid withthe casing of the carburetor, this screw 34 serving chiefly to limit theminimum opening, corresponding to idling with the engine Warm, ofthrottle valve 6. The angular position of lever 21 and consequently theminimum degree of opening of throttle valve 6 are determined by athermostatic device comprising a material 24 contained in a closedcasing 25 and capable of undergoing a substantial variation of volumewhen passing in reversible fashion from one physical state to anotherone and in particular from the solid or pasty state to the liquid statebetween the temperatures to which it is subjected according as theengine is cold or warm. In order to transmit to the outside the effectsdue to the variations of volume of material 24, a push-piece 26 extendsto the outside of casing 25. This casing 25 is fixed in a chamber 14 bya screw 36 which applies said casing against an annular packing joint37.

Casing 25 is subjected to the temperature of a fluid which becomesheated at the same time as engine is growing warm. This fluid mayconsist, for instance, of the exhaust gases of the engine, of air heatedby these gases, of the cooling water of the engine or of the lubricatingoil of said engine. For these purposes chamber 14 is provided with aninlet conduit 30 and an outlet 31 for said fluid. According to amodification casing 25 might be subjected to the temperature of anelectric resistor fed with current as soon as the engine is started.

Lever 21 is subjected, in the direction which corresponds to the closingof throttle valve 6, to the action of thermostatic device 2426 and, inthe direction which corresponds to the opening of said throttle valve 6to the action of a spring 28a bearing upon an abutment 38 rigid with theframe of the carburetor. Spring 28a is chosen sufficiently strong toovercome the action of return spring 10.

Concerning now the control of choke valve 3 in accordance with thetemperature of the engine it is ensured by thermostatic device 24-26itself. For this purpose, choke valve 3 is urged in the closingdirection by a return spring 39 secured to the upper end 21b of lever 21so that the force exerted by this spring 39 upon choke valve 3 decreaseswhen the temperature of material 24 increases and inversely.

As shown by FIGS. 1 to 3, spring 39 is secured to a lever 13 rigid withshaft 4. According to the modifica tion of FIG. 4, spring 39 is securedto a flexible strip or wire 40 which passes around a cam 41 rigid withshaft 4.

Finally, according to a known arrangement there is secured to the end oflever 13 (or cam 41) a rod 18 pivoted at its other end to a piston 17slidable in a cylinder 42, this cylinder being connected through a pipe16 to the portion of induction pipe 1 located downstream of throttlevalve 6. A groove 20 and an orifice 19 opening into a groove of piston17 permit of adjusting the displacement of piston 17 under the effect ofthe suction transmitted through pipe 16 when the action of spring 39 issufliciently strong to prevent a full displacement of piston 17 towardthe left (FIGS. 1, 3 and 4).

The carburetor such as above described works in the following manner.When the engine is cold (FIG. 1) push-piece 26 is wholly retracted withrespect to its casing and spring 28a pushes lever 21 toward saidpush-piece so that the degree of opening of throttle valve 6 (determinedby the cooperation of screw 22 with said lever) is relatively great.When the engine has warmed up (FIG. 3) push-piece 26 is driven outwardlyand pushes lever 21 toward the left against the action of spring 28a sothat the degree of opening of throttle valve 6 for idling running isreduced.

On the other hand, when the engine is cold the pivoting of lever 21toward the right increases the pull exerted through spring 39 on chokevalve 3. This produces, other things being equal, a greater closing ofchoke valve 3 and therefore a greater suction downstream of this chokevalve and finally a greater feed of fuel into venturi 5. Thecharacteristics of spring 39 and the shape of cam 41 (if such a cam isused, according to FIG. 4) are determined in such manner that the law ofvariation, as a function of the temperature, of the force tending toclose choke valve 3 is in accordance with the requirements forsatisfactorily starting the engine from cold.

As soon as the engine is started, piston 17 is driven toward the left ofFIG. 1 by the suction transmitted through pipe 16 and this displacementis limited by the communication opened between groove 20 and orifice 19.The length of groove 20 is calculated so that the degree of opening ofchoke valve 3 in these conditions corresponds to the running of theengine when cold.

As thermostatic device 24-26 is being more and more heated, lever 21pivots toward the left and, as above explained, gradually moves throttlevalve 6 toward the idling running position suitable when the engine iswarm. At the same time, the end 21b of lever 21 moves towards the leftand thus reduces the pull exerted by spring 39 which enables choke valve3 to open to a greater degree either under the effect of the air streamindicated by the arrow of FIG. 2 or through the action of piston 17which has a tendency to move towards the left.

When the engine, and consequently thermostatic device 24-26, aresufficiently warm, the pull exerted by spring 39 is practically zero forthe position of complete opening of choke valve 3. At the same timescrew 34 has come into contact with abutment 35 and this limits theopening of throttle valve 6 to the minimum corresponding to idlingrunning when the engine is Warm, whereas the portion 21a of lever 21 canmove away from screw 22 and take the positions imparted thereto bypushpiece 26.

As soon as screw 34 has come into contact with abutment 35 (FIG. 3), theposition of lever 21 no longer has any action upon throttle valve 6 andon the other hand it no longer influences the force tending to closechoke valve 3.

The law of variation of this force as a function of the angular positionof choke valve 3 depends, in the construction of FIGS. 1 to 3, upon theangle made by lever 13 with the longitudinal axis of spring 39 and inthe case of the construction of FIG. 4 upon the shape of cam 41, theconstruction of FIG. 4 permitting a more accurate adjustment of saidvariation.

The above described embodiment of the invention is given merely by wayof example.

What I claim is:

1. An internal combustion engine carburetor which comprises, incombination,

an induction pipe,

a choke valve in said pipe,

a throttle valve in said pipe downstream of said choke valve, saidthrottle valve being rotatable about an axis fixed with respect to saidpipe,

a projection rigid with said throttle valve,

a lever pivoted to said pipe about said axis and having a portionthereof arranged to form an abutment adapted to cooperate with saidthrottle valve projection for controlling the idling running position ofsaid throttle valve,

throttle valve return spring means for urging said throttle valveprojection toward contact with said abutment,

a casing mounted in fixed position with respect to said induction pipe,close thereto,

a mass of material enclosed in said casing capable of undergoing a greatvariation of volume when passing from one physical state to another in areversible maner, in response to variation of its temperature from onegiven value to another one,

a push-piece partly embedded in said mass of material and movable withrespect to said casing transversely to said axis, said push-piecedirectly bearing against one side of said lever for pivoting it in onedirection in response to variations of volume of said mass of material,

means for subjecting said casing to one temperature when the engine iscold and to another temperature when the engine is warm,

lever return spring means operable on said lever in the other directionfor pivoting it about said axis in said other direction in response toreverse variations of the volume of said mass of material,

said lever return spring means being capable, upon such reversevariation of volume of said mass of material of moving said leveragainst the action of said throttle valve return spring means,

and a spring interposed between said lever and said choke valve to urgesaid choke valve in the closing direction in response to said reversevariations of volume of said mass of material.

2. A carburetor according to claim 1 comprising a spindle rigid withsaid throttle valve and journalled with respect to said pipe about saidaxis, said lever being freely journalled about said spindle.

References Cited by the Examiner UNITED STATES PATENTS 1,894,354 l/1933Kommer et al 261-52 2,124,778 7/1938 Hunt 26152 2,774,343 12/1956Schaffer et a1. 261-39 2,957,465 10/1960 Wagner 26139 HARRY B. THORNTON,Primary Examiner.

T. R. MILES, Assistant Examiner.

1. AN INTERNAL COMBUSTION ENGINE CARBURETOR WHICH COMPRISES, INCOMBINATION, AN INDUCTION PIPE, A CHOKE VALVE IN SAID PIPE, A THROTTLEVALVE IN SAID PIPE DOWNSTREAM OF SAID CHOKE VALVE, SAID THROTTLE VALVEBEING ROTATABLE ABOUT AN AXIS FIXED WITH RESPECT TO SAID PIPE, APROJECTOR RIGID WITH SAID THROTTLE VALVE, A LEVER PIVOTED TO SAID PIPEABOUT SAID AXIS AND HAVING A PORTION THEREOF ARRANGED TO FORM ANABUTMENT ADAPTED TO COOPERATE WITH SAID THROTTLE VALVE PROJECTION FORCONTROLLING THE IDLING RUNNING POSITION OF SAID THROTTLE VALVE, THROTTLEVALVE RETURN SPRING MEANS FOR URGING SAID THROTTLE VALVE PROJECTIONTOWARD CONTACT WITH SAID ABUTMENT, A CASING MOUNTED IN FIXED POSITIONWITH RESPECT TO SAID INDUCTION PIPE, CLOSE THERETO, A MASS OF ENCLOSEDIN SAI CASING CAPABLE OF UNDERGOING A GREAT VARIATION OF VOLUME WHENPASSINF FROM ONE PHYSCIAL STATE TO ANOTHER IN A REVERSIBLE MANNER, INRESPONSE TO VARIATION OF ITS TEMPERATURE FROM ONE GIVEN VALUE TO ANOTHERONE, A PUSH-PIECE PARTLY EMBEDDED IN SAID MASS OF MATERIAL AND MOVABLEWITH RESPECT TO SAID CASING TRANVERSELY TO SAID AXIS, SAID PUSH-PIECEDIRECTLY BEARING AGAINST ONE SIDE OF SAID LEVER FOR PIVOTING IT IN ONEDIRECTION IN RESPONSE TO VARIATIONS OF VOLUME OF SAID MASS OF MATERIAL,MEANS FOR SUBJECTING SAID CASING TO ONE TEMPERATURE WHEN THE ENGINE ISCOLD AND TO ANOTHER TEMPERATURE WHEN THE ENGINE IS WARM, LEVER RETURNSPRING MEANS OPERABLE ON SAID LEVER IN THE OTHER DIRECTION FOR PIVOTINGIT ABOUT SAID AXIS IN SAID OTHER DIRECTION IN RESPONSE TO REVERSEVARIATIONS OF THE VOLUME OF SAID MASS OF MATERIAL, SAID LEVER RETURNSPRING MEANS BEING CAPABLE, UPON SUCH REVERSE VARIATION OF VOLUME OFSAID MASS OF MATERIAL OF MOVING SAID LEVER AGAINST THE ACTION OF SAIDTHROTTLE VALVE RETURN SPRING MEANS, AND A SPRING INTERPOSED BETWEEN SAIDLEVER AND SAID CHOKE VALVE TO URGE SAID CHOKE VALVE IN THE CLOSINGDIRECTION IN RESPONSE OF SAID REVERSE VARIATIONS OF VOLUME OF SAID MASSOF MATERIAL.